High School Science. Basic Skills 101

Transcription

1 High School Science Basic Skills 101 a comprehensive list of what you should know (lab reports, science safety, lab equipment, metric conversions, charts & graphs)

2 Scientific Processes Scientific Method: Writing a lab report Your will be expected to use the following basic guidelines to write up formal lab reports. This may be modified for use in high school. Guidelines for Lab Write-Ups (Each of these sections needs to be labeled and visibly obvious) Title: An appropriate title which highlights what the lab is about. Background: This section includes information from the introduction on the lab handout and/or tet and class notes. Purpose/Problem/Objective: The problem being investigated phrased as a question which does not lead to a yes/no answer. Hypothesis: A prediction of the outcome of the investigation. This should incorporate what is being manipulated, what the outcome will be and why. One way to do this is an if then, because statement. This should be stated in third person. Variables should be identified here. Hint: The Independent Variable is the one I change and the Dependent Variable is the one that responds to the change. Materials: A list of all of the materials in column form. Materials must be quantified in metric units and described. (Include how many, how much and what kind.) Procedure: In your own words; a numbered list of steps in the appropriate order. (Metric measurements must be included in quantities used.) This should be stated in the third person. Data/Observations: Includes data collected in the form of tables, charts, graphs and illustrations. A separate section for calculations is included here if necessary. Analysis: This is where you verbally analyze the quantifiable results if necessary. This section is included when numerical data is collected. Conclusion: This is where you will summarize your results, and refer back to your hypothesis. You need to state whether it was upheld (correct) or not, giving reasons for your conclusions. If your hypothesis was not upheld, you need to be able to explain any error that may have contributed to this. You may also include any personal reflections about this investigation in this section. Questions: Many labs will have questions to be answered at the end. These are to be answered here.

3 Determining the problem/purpose/objective and hypothesis The problem of your scientific investigation is the question that the investigation is trying to answer. Example: If you were doing an experiment to determine the effect of fertilizer on the growth of a bean plant, you would first determine your problem and phrase it as a question. Here the problem would be How does fertilizer affect the growth of bean plants? (The question should not lead to a yes or no answer.) Now that you have identified the problem, you must hypothesize what you think the results of the experiment will be. Example: If a scientist plants bean plants using Miracle-Gro fertilizer, the plants will grow taller than plants fertilized with other brands. This is because Miracle-Gro uses nitrogen, phosphorus and potassium for optimal growth. Your hypothesis must always relate to your problem as stated in the lab. Don t forget that the conclusion must related back to your hypothesis as well. Variables and controls Variables are those factors being tested in an experiment, which are usually compared to a control. A control is a known measure to which scientists can compare their results. The independent variable (or manipulated variable) is the variable which the experimenter is changing. Example: Brands of fertilizer. The dependent variable (or responding variable) is the variable which responds to the change made by the experimenter. It is the measured result. Example: Plant height. Hint to remember: the dependent variable depends on what you changed as the independent variable.

4 Analyzing data and drawing conclusions Data is what is collected during the scientific investigation, whether it is numbers/quantities or observations. This is reported in tables, charts and graphs. (See graphing section of this booklet.) The analysis step is very important as it transforms raw data (numbers) into information, which can be used to report results in a user-friendly format. The conclusion is a brief summary of the results of the investigation. The analyzed data is interpreted and the result is your conclusion. You must always refer back to your proposed hypothesis and tell whether the results supported the hypothesis or not. Example: The experiment showed that Granny s Bloomers brand fertilizer led to greater plant growth than all other brands of fertilizer and that of the control group with no fertilizer. Therefore, the hypothesis was proved to be incorrect because Granny s Bloomers brand fertilizer proved to yield greater plant growth than Miracle-Gro brand fertilizer. Scientific Notation In science we often work with very small and very large numbers. Scientific notation is a way of writing these numbers to make them more manageable. A number in scientific notation always includes a single nonzero digit followed by a decimal multiplied by a power of 10. For example: 370 = 3.7 x = x = 9.1 x 10-6

5 The Metric System The mnemonic device King Henry died by drinking chocolate milk can help you remember the metric prefixes. King Henry Died By Drinking Chocolate Milk Prefixes kilo- hecto- deca- base unit deci- centi- milli- Abbreviations Mass kg hg dag gram dg cg mg Length km hm dam meter dm cm mm Volume kl hl dal liter dl cl ml Meaning 1000x 100x 10x 1 0.1x 0.01x 0.001x Examples Mass 1 kg = 1000 g 1 hg = 100 g 1 dag = 10 g 1 g 1 dg = 0.1 g 1 cg = 0.1 g 1 mg = g Length 1 km = 1000 m 1 hm = 100 m 1 dam = 10 m 1 m 1 dm = 0.1 m 1 cm = 0.1 m 1 mm = m Volume 1 kl = 1000 L 1 hl = 100 L 1 dal = 10 L 1 L 1 dl = 0.1 L 1 cl = 0.1 L 1 ml = L Another way to look at this chart is in a line: Move decimal to the Left Kilo Hecto Deca Base Deci Centi Milli Move decimal to the Right A second way to represent the metric system is the stair step model. Kilo Hecto Deca Base Move decimal to the Right Move decimal to the Left Deci Centi Milli

6 Lab Equipment Safety Symbols Although these symbols are commonly used, you may see variations as well. Wear Lab Apron Biological Hazard Sharp Object Safety Disposal Alert Wear Goggles Acid Hazard Poison Electrical Safety Equipment Used in Measuring Measurement Definition Common Unit(s) Instrument mass amount of matter gram (g) Balance triple beam balance electronic balance

7 weight force exerted by gravity on matter Newton (N) Spring scale length straight line distance between two points meter (m) or centimeter (cm) Ruler meter stick centimeter ruler volume space occupied by matter Liter (L) or milliliter (ml) Graduated cylinder time continuum from past to present to future seconds (s) or minutes (m) Timepiece clock watch stopwatch temperature is related to the average kinetic energy of the molecules of matter degrees Celsius ( C) or Kelvin (K) Thermometer Other Equipment

8 beaker Instrument Uses Picture Holding liquids beakers are not used to measuring volume funnel test tube holder Bunsen burner Separating liquid matter from solid matter (with filter paper) Holding test tubes near the flame of a Bunsen burner Heating matter to high temperatures spatual, scoopula or spoon Handling solid substances evaporating dish and watch glass dropper pipette Heating solutions or solids to remove the water Measuring small amounts of liquid hot plate Heating liquids in beakers test tubes Heating liquids or solids test tube brush Cleaning test tubes

9 ring stand Supporting test tubes beakers and funnels iron ring & wire gauze Supporting beakers or funnels on the ring stand iron ring wire gauze flint striker utility clamp Measuring pipet stirring rod Providing sparks to light the Bunsen burner Holding test tubes on the ring stand Measuring volume of liquids Mixing liquids spot plate Holder for mixing liquids rubber stoppers Covering test tubes, holding glass tubing and thermometers microscope Enlarging images of small objects and biological specimens dissecting probe forceps Pointing to and separating parts of a biological specimen Handling biological specimens and chemicals

10 microscope slides and cover slips Holding small objects and biological specimens for viewing with the microscope deep well microscope slide goggles Holding live microscopic specimens for viewing Protecting eyes from laboratory hazards apron Protecting clothing form laboratory hazards Organizing Data in Charts/Tables 1 Tables A table is used to arrange data so it is easy to read and compare. A table should have a title telling the reader what is being presented. Create lines dividing the table into columns and rows. The columns should be titled with the items being compared. The row headings should identify the specific characteristics being compared among those (column) items. Within the grid of the table, the collected data should be recorded and labeled. Example: Fertilizer Brand Granny s Bloomers Jobe s House Plant Spikes The Effect of Fertilizers on Bean Plant Growth Pea Plant Height in cm (6 plants (A-F) for each fertilizer) A B C D E F average Miracle-Gro K-Mart Fertilizer None Glencoe Skill Handbook

11 Pulse Rate in Beats Per Minute Average Height in cm Bar Graphs A bar graph is used to show relationships between groups. The two items being compared do not need to affect each other. It s a fast way to show big differences. Notice how easy it is to see what was done in the experiment below with bean plant growth and different brands of fertilizer. Example: The Effect of Fertilizers on Bean Plant Growth Granny's Bloomers Jobe's House Plant Spikes Miracle-Gro K-Mart Fertilizer None Fertilizer Brand Line Graphs A line graph is used to show continuing data; how one thing is affected by another. The most common (appropriate) use of the line graph is describing events that show changes over time. It is clear to see how things are progressing by examining the rise and fall of the line graph. This kind of graph is needed to show the effect of an independent variable (x-axis) on a dependent variable (y-axis). In the sample below, the pulse rate of a person is shown to change over time; as time continues the pulse rate changes. Example: Exercise and Pulse Rate Time in Minutes Mabel - 36 year old office worker Albert - 26 year old former college athlete

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13 Circle Graphs (pie charts): A circle graph is used to show how a part of something relates to the whole. This kind of graph is needed to show percentages effectively. To create a pie chart 2 1) Find the sum of all of the data. (Call it s). If you took a survey and asked 56 people which color M&M candies is their favorite, s = 56. 2) Divide the amount in each category by s. This will be the percentage of responses for each category compared to the total amount of data. For example, if you asked people about their favorite M&M choice and of the 56 people surveyed, 7 of them said red, then 7/56 or or 12.5% of the people surveyed picked red. You would, of course, have to calculate the percentage of people that choose the other colors as well. 3) Each piece of pie should represent the percentage of the circle that is equal to the percentage of s. So for example, a pie piece representing the number of people who liked red would be 12.5% of the circle. Since a complete circle is 360 then the red piece would have a central angle equal to (0.125 x 360 = 45 ). Calculate the central angle for each piece and you have the pie chart. Example: Twin Groves Ice Cream Survey 17% 6% 21% Vanilla 21.0% Chocolate 33.0% Strawberry 12.0% Raspberry 4.0% 7% Peach 7.0% Neopolitan 17.0% 4% Other 6.0% 12% 33% 2 Charts & Graphs 2/2/06 2:54 p.m.

14 Research Skills What students should be able to accomplish to be information literate. Locate the sources 1. Identify the sources in your classroom and home environments (i.e. textbooks, magazines, encyclopedias, internet) 2. Find additional sources in the school or public libraries. Use the electronic catalog to determine the location of each source and whether or not it is available. Write down the location number for each source. Use the library map to determine the physical location of each source. Go to the location of each source in the library. Finding information within the sources 1. Use the Table of Contents, Glossary, and Index to locate specific information within each source. 2. Browse the shelves for your topic s location number to locate other source on your topic. Organizing information from multiple sources 1. Put note cards (from multiple sources) in logical order. 2. Develop an outline (storyboard, script, etc.) for the topic. 3. Write a bibliography and include it in your project. It is always important to tell where you got the information you used. Citation Formulas, MLA and APA EasyBib EasyBib is a free automatic bibliography composer. It formats, alphabetizes, and prepares your MLA works cited list for printing. Assimilation Assimilation is the process of gathering facts and information about an event or phenomenon for the purpose of understanding it. Below is a list of websites that aid in gathering information